Outcomes and Patterns of Failure in Early-Stage, High-Risk Histology Endometrial Cancer Treated with Vaginal Cuff Brachytherapy

Abstract

<h3>Purpose/Objective(s)</h3> The majority of patient diagnosed with endometrial cancer have low-risk endometrioid histology with an excellent prognosis. There is a small subset of patients however, who are diagnosed with a histology for which the outcomes are not as good. Serous, clear cell, carcinosarcoma and neuroendocrine carcinomas are more aggressive histological variants with a propensity for early extrauterine spread resulting in higher rates of death. They typically receive upfront chemotherapy but questions remain as to whether the increased risk of spread warrants adjuvant pelvic radiation or whether the risk can be mitigated with vaginal cuff brachytherapy (VCB). We aim to describe the outcomes and patterns of failure in early-stage, high-risk histology patients in which pelvic radiation was omitted, in order to shed light on the risk of pelvic failure. <h3>Materials/Methods</h3> A retrospective chart review was performed on patients treated for high-risk histology, early-stage uterine cancer at our institution. Patients receiving adjuvant VCB +/- chemotherapy were included. Demographic and clinical data was collected. Descriptive statistics were used to summarize variables. Kaplan-Meier analysis was used to estimate the survival probabilities. For all time to event outcomes, univariate cox proportional hazard regression models were built for clinically correlated variables. A two-tailed p<0.05 was considered statistically significant. <h3>Results</h3> 77 patients with early-stage carcinosarcoma (23.4%), clear cell (35.1%), serous (40.3%) and neuroendocrine carcinoma (1.3%) of the uterus were reviewed. Median follow up was 43 months (range 7-117 months). 2yr and 5yr overall survival (OS), metastasis free survival (MFS) and progression free survival (PFS) were 95% and 92%, 95% and 90% and 91% and 82% respectively. Of the 9 patients (11.7%) that recurred, 2 patients (2.6%) had isolated vaginal cuff recurrences, 4 patients (5.2%) had isolated pelvic recurrences and 3 patients (3.9%) had both a local and distant failure. Of the 27 individual sites of recurrence, 21 (77.8%) were below the level of L4. <h3>Conclusion</h3> In patients with early stage, high risk histology endometrial cancer treated with adjuvant VCB +/- chemotherapy, the 2yr and 5yr PFS was 91% and 82% respectively. All patients that recurred had some component of pelvic failure.